The present invention relates to disk and doughnut contacting arrangements, and, more particularly, to disk and doughnut contacting arrangements suitable for use in pulsed disk and doughnut extraction columns.
In liquid-liquid extraction columns, one liquid may form a continuous phase flowing in one direction along the column and another liquid may form a dispersed phase flowing in the opposite direction. The countercurrent flow is maintained in the equipment by the difference in densities of the liquids and by the force of gravity. Both streams may be pumped through the column at various desired linear velocities.
In many cases, the density difference between the liquids is insufficient to disperse one liquid in the other and to keep turbulence at a requisite level for efficient mass transfer.
Various mechanical stirring or pulsating devices may apply additional energy needed for reaching the desired turbulence. U.S. Pat. No. 2,601,674 to Reman et al., for instance, teaches a rotary disk contactor, while U.S. Pat. No. 4,200,522 to Karr discloses a reciprocating plate column. U.S. Pat. No. 2,011,186 to Van Dijk teaches a pulsed column.
The present inventors have recognized a need for improved disk and doughnut extraction columns.